Camera module for vehicular vision system

ABSTRACT

A camera module for a vehicular vision system includes a front camera housing having a housing portion and a cylindrical lens barrel extending from the housing portion and accommodating a lens. An imager printed circuit board is attached at the front camera housing portion. With the imager printed circuit board attached at the front camera housing, the imager is optically aligned with an optical axis of the lens. A rear camera housing portion is mated with the housing portion of the front camera housing so as to encase the imager printed circuit board in the camera module. The housing portion of the front camera housing includes mounting structure configured to mount the camera module at a vehicle. The lens barrel includes a material having a lower coefficient of thermal expansion as compared to the material of the front camera housing.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 16/165,170, filed Oct. 19, 2018, now U.S. Pat. No. 10,750,064,which claims the filing benefits of U.S. provisional application Ser.No. 62/575,650, filed Oct. 23, 2017, which is hereby incorporated hereinby reference in its entirety.

FIELD OF THE INVENTION

The present invention relates generally to a vehicle vision system for avehicle and, more particularly, to a vehicle vision system that utilizesone or more cameras at a vehicle.

BACKGROUND OF THE INVENTION

Use of imaging sensors in vehicle imaging systems is common and known.Examples of such known systems are described in U.S. Pat. Nos.5,949,331; 5,670,935 and/or 5,550,677, which are hereby incorporatedherein by reference in their entireties. Various cameras have beenproposed for such imaging systems, including cameras of the typesdescribed in U.S. Pat. No. 7,965,336 and U.S. Publication No.US-2009-0244361, which are hereby incorporated herein by reference intheir entireties.

SUMMARY OF THE INVENTION

The present invention provides a vision system or imaging system for avehicle that utilizes one or more cameras to capture image datarepresentative of images exterior of the vehicle. The camera or cameramodule comprises an imager and a circuit board (or circuit boards) and alens. The lens comprises a plurality of optical elements fixedlydisposed in a lens barrel. A front camera housing portion is configuredto receive an imager printed circuit board therein, with the imagerprinted circuit board disposed at the lens barrel and bonded thereatwith the imager optically aligned with an optical axis of the opticalelements. The lens barrel and the front camera housing portion areintegrally formed together as a single part. The front camera housingportion includes mounting structure configured to mount the cameramodule at a vehicle. A rear camera housing portion is mated with a rearportion of the front camera housing so as to encase and seal the imagerprinted circuit board in the camera module. The mounting structure isformed as part of the front camera housing so as to be evenly orcentrally located about the optical axis and about a center of mass ofthe camera module. Circuitry of the camera module is electricallyconnected to the imager and is electrically connected to electricalconnecting elements that are configured to electrically connect to awire harness of the vehicle.

Optionally, the rear camera housing portion may comprise a heat sink.Optionally, the optic elements may be fixedly bonded to the lens barrel.

These and other objects, advantages, purposes and features of thepresent invention will become apparent upon review of the followingspecification in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a vehicle with a vision system thatincorporates cameras in accordance with the present invention; and

FIG. 2 is a sectional view of a camera module in accordance with thepresent invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A vehicle vision system and/or driver assist system and/or objectdetection system and/or alert system operates to capture images exteriorof the vehicle and may process the captured image data to display imagesand to detect objects at or near the vehicle and in the predicted pathof the vehicle, such as to assist a driver of the vehicle in maneuveringthe vehicle in a rearward direction. The vision system includes an imageprocessor or image processing system that is operable to receive imagedata from one or more cameras and provide an output to a display devicefor displaying images representative of the captured image data.Optionally, the vision system may provide display, such as a rearviewdisplay or a top down or bird's eye or surround view display or thelike.

Referring now to the drawings and the illustrative embodiments depictedtherein, a vehicle 10 includes an imaging system or vision system 12that includes at least one exterior facing imaging sensor or camera,such as a rearward facing imaging sensor or camera 14 a (and the systemmay optionally include multiple exterior facing imaging sensors orcameras, such as a forward facing camera 14 b at the front (or at thewindshield) of the vehicle, and a sideward/rearward facing camera 14 c,14 d at respective sides of the vehicle), which captures images exteriorof the vehicle, with the camera having a lens for focusing images at oronto an imaging array or imaging plane or imager of the camera (FIG. 1).Optionally, a forward viewing camera may be disposed at the windshieldof the vehicle and view through the windshield and forward of thevehicle, such as for a machine vision system (such as for traffic signrecognition, headlamp control, pedestrian detection, collisionavoidance, lane marker detection and/or the like). The vision system 12includes a control or electronic control unit (ECU) or processor 18 thatis operable to process image data captured by the camera or cameras andmay detect objects or the like and/or provide displayed images at adisplay device 16 for viewing by the driver of the vehicle (althoughshown in FIG. 1 as being part of or incorporated in or at an interiorrearview mirror assembly 20 of the vehicle, the control and/or thedisplay device may be disposed elsewhere at or in the vehicle). The datatransfer or signal communication from the camera to the ECU may compriseany suitable data or communication link, such as a vehicle network busor the like of the equipped vehicle.

The control unit may comprise or may be part of an autonomous vehiclecontrol system, whereby the cameras capture image data that is processedfor use in autonomously controlling the vehicle. Optical axis alignmentand focus requirements are very precise for autonomous vehicle cameras.Typical automotive cameras require that they maintain alignment towithin +/−1 degree, whereas autonomous vehicle cameras may haverequirements that are hundreds of times smaller. Also, typical camerasmay have a greater than about 40 μm range of focus, whereas autonomousvehicle cameras may have less than about 10 μm range of focus.

Cameras comprise many interfacing components along the optical axiswhich may shift when exposed to thermal changes, vibrations ormechanical shocks. Some typical interfaces include: (1) Lenselements-to-lens barrel, (2) Lens barrel-to-lens holder, (3) Lensholder-to-image sensor PCB, (4) Lens holder-to-camera front housing, (5)Camera front housing-to-camera rear housing and mounting features,and/or (6) Camera rear housing mounting features to Camera bracket. Eachof these contribute to the current alignment and focus toleranceexpected for standard automotive cameras today.

The “high precision camera” of the present invention minimizes alignmentand focus change. For example, while lens elements are typically placedwithin a “barrel” with some small amount of clearance and held in placewith a compression force, the camera of the present invention has itslens elements permanently bonded in place in the lens barrel to preventshifting.

Also, the camera directly adhesively bonds the image sensor PCB (printedcircuit board) at the lens or lens barrel. To eliminate all sources ofmovement between the lens and image sensor, the imager or its printedcircuit board is bonded directly to the lens structure or lens barrel,such as via a suitable quick-cure adhesive (see FIG. 2). The bondingadhesive also acts as the pliable assembly element or member between theoptics and the imager or imaging sensor for the focus and alignmentsteps (and then cures to a cured state that retains the imager PCB andimager relative to the lens barrel and lens). For example, the adhesiveand focus and alignment steps may utilize aspects of the cameras andprocesses described in U.S. Pat. Nos. 8,542,451 and 9,277,104, which arehereby incorporated herein by reference in their entireties. Forexample, the adhesive and focus and alignment steps may utilize aspectsof the cameras and processes described in U.S. Pat. Nos. 8,542,451 and9,277,104, which are hereby incorporated herein by reference in theirentireties.

The camera also includes a unified lens and camera body structure. Toeliminate the lens-to-camera body structure interface, these are asingle piece or single construction. The lens barrel structure isextended to also become the camera body and includes the camera mountingfeatures (that mount the camera at the vehicle, such as via fasteners orthe like).

The structural rigidity and load balance or load symmetry are importantfor maintaining the camera's aim during dynamic conditions such asvehicle vibration. Thus, the mounting features are evenly or centrallylocated about the camera optical axis and center of mass of the camera.

Symmetrical heat distribution about the optical axis or key structuresof the camera also becomes very important for these high levels ofprecession. The camera of the present invention is designed to evenlydistribute heat about the optical axis and includes sources of heatdissipation, such as cooling fins or mounting features, positioned to dothe same. This typically means being symmetrically positioned as well aspossible round the optical axis.

If required for athermalization, the lens barrel may be constructed froma material with a lower CTE (coefficient of thermal expansion), such astitanium or the like, or a higher CTE, such as a zinc alloy or the like,to provide a focus CTE that is selected to maintain focus of images atthe imager in varying temperatures. Optionally, a bridge member may beincluded between the lens barrel and image sensor to compensate forthermal effects. Such a bridge member may be permanently bonded to thelens barrel.

The camera may reduce moisture air in the camera module or body by wayof desiccant, nitrogen bath assembly or other gas to prevent internalcondensation on cooled components. Optionally, for example, a desiccantsheet with adhesive backing may be used. Optionally, a heat spreader,such as one made from graphite (such as a graphite sheet or layer orfilm, or such as another suitable heat spreading or heat diffusing sheetor layer or film, such as, for example, a graphene sheet or layer orfilm or the like), may be used to enhance the rear cover sink ability.

Thus, and such as shown in FIG. 2, the camera module of the presentinvention includes a lens barrel and camera upper or front housingportion that are formed as a single or unitary part (such as viainjection molding of a plastic material). The lens optics are fixed orbonded in the lens barrel and the imager (or imager PCB) is adhered orbonded or attached (such as via a compliant quick-cure adhesive)directly to the lens barrel system and positioned for focus andalignment. The camera mounting features (that are configured to mount orattach the camera at the vehicle) are formed as part of the lens barreland housing portion and are located about the camera optical axis andcenter of mass of the camera.

In the illustrated embodiment, the camera module includes two printedcircuit boards (in addition to the imager PCB) that include circuitryassociated with the imager and camera. Circuitry of the PCBs and of thecamera module is electrically connected to the imager and iselectrically connected to electrical connecting elements that areconfigured to electrically connect to a wire harness of the vehicle. Oneof the PCBs may include an image processor disposed thereat. The thermalelement may be in contact with the PCB having the processor, and may bein contact at or the processor, so as to draw heat generated by theprocessor away from the processor and its PCB and toward the rear of thecamera housing. For example, the thermal element may engage the rearsurface of the processor PCB at or near or opposite from the processor.

As shown in FIG. 2, the thermal element is in thermal conductive contactwith the rear housing or cover and the heat sink, and extends therefrominto the cavity of the camera module. The end of the thermal elementthat is distal from the rear housing is in thermal contact with theimager PCB (at the rear or opposite side of the imager PCB from wherethe imager is disposed). The thermal element protrudes through anaperture or hole through one or more other PCBs, which are centrallyaligned with the axis of the camera module and lens assembly. Thedesiccant sheet and/or heat spreader may be disposed at the interiorsurface of the rear housing portion and between the rear housing portionand the thermal element (which may be fastened to the rear housingportion via fasteners or the like) to spread the heat conducted by thethermal element (drawn from the PCB(s)) over the rear housing portionand heat sink to enhance cooling of the camera module during operation.

The camera module may utilize aspects of the cameras and connectorsdescribed in U.S. Pat. Nos. 9,621,769; 9,596,387; 9,277,104; 9,077,098;8,994,878; 8,542,451 and/or 7,965,336, and/or U.S. Publication Nos.US-2009-0244361; US-2013-0242099; US-2014-0373345; US-2015-0124098;US-2015-0222795; US-2015-0327398; US-2016-0243987; US-2016-0268716;US-2016-0286103; US-2016-0037028; US-2017-0054881; US-2017-0133811;US-2017-0201661; US-2017-0280034; US-2017-0295306; US-2017-0302829and/or US-2018-0098033, and/or U.S. patent applications, Ser. No.16/165,204, filed Oct. 19, 2018, and published on Apr. 25, 2019 as U.S.Publication No. US-2019-0124243, and/or Ser. No. 16/165,253, filed Oct.19, 2018, now U.S. Pat. No. 10,678,018, which are hereby incorporatedherein by reference in their entireties.

The camera or sensor may comprise any suitable camera or sensor.Optionally, the camera may comprise a “smart camera” that includes theimaging sensor array and associated circuitry and image processingcircuitry and electrical connectors and the like as part of a cameramodule, such as by utilizing aspects of the vision systems described inInternational Publication Nos. WO 2013/081984 and/or WO 2013/081985,which are hereby incorporated herein by reference in their entireties.

The system includes an image processor operable to process image datacaptured by the camera or cameras, such as for detecting objects orother vehicles or pedestrians or the like in the field of view of one ormore of the cameras. For example, the image processor may comprise animage processing chip selected from the EYEQ™ family of image processingchips available from Mobileye Vision Technologies Ltd. of Jerusalem,Israel, and may include object detection software (such as the typesdescribed in U.S. Pat. Nos. 7,855,755; 7,720,580 and/or 7,038,577, whichare hereby incorporated herein by reference in their entireties), andmay analyze image data to detect vehicles and/or other objects.Responsive to such image processing, and when an object or other vehicleis detected, the system may generate an alert to the driver of thevehicle and/or may generate an overlay at the displayed image tohighlight or enhance display of the detected object or vehicle, in orderto enhance the driver's awareness of the detected object or vehicle orhazardous condition during a driving maneuver of the equipped vehicle.

For example, the vision system and/or processing and/or camera and/orcircuitry may utilize aspects described in U.S. Pat. Nos. 9,233,641;9,146,898; 9,174,574; 9,090,234; 9,077,098; 8,818,042; 8,886,401;9,077,962; 9,068,390; 9,140,789; 9,092,986; 9,205,776; 8,917,169;8,694,224; 7,005,974; 5,760,962; 5,877,897; 5,796,094; 5,949,331;6,222,447; 6,302,545; 6,396,397; 6,498,620; 6,523,964; 6,611,202;6,201,642; 6,690,268; 6,717,610; 6,757,109; 6,802,617; 6,806,452;6,822,563; 6,891,563; 6,946,978; 7,859,565; 5,550,677; 5,670,935;6,636,258; 7,145,519; 7,161,616; 7,230,640; 7,248,283; 7,295,229;7,301,466; 7,592,928; 7,881,496; 7,720,580; 7,038,577; 6,882,287;5,929,786 and/or 5,786,772, and/or U.S. Publication Nos.US-2014-0340510; US-2014-0313339; US-2014-0347486; US-2014-0320658;US-2014-0336876; US-2014-0307095; US-2014-0327774; US-2014-0327772;US-2014-0320636; US-2014-0293057; US-2014-0309884; US-2014-0226012;US-2014-0293042; US-2014-0218535; US-2014-0218535; US-2014-0247354;US-2014-0247355; US-2014-0247352; US-2014-0232869; US-2014-0211009;US-2014-0160276; US-2014-0168437; US-2014-0168415; US-2014-0160291;US-2014-0152825; US-2014-0139676; US-2014-0138140; US-2014-0104426;US-2014-0098229; US-2014-0085472; US-2014-0067206; US-2014-0049646;US-2014-0052340; US-2014-0025240; US-2014-0028852; US-2014-005907;US-2013-0314503; US-2013-0298866; US-2013-0222593; US-2013-0300869;US-2013-0278769; US-2013-0258077; US-2013-0258077; US-2013-0242099;US-2013-0215271; US-2013-0141578 and/or US-2013-0002873, which are allhereby incorporated herein by reference in their entireties. The systemmay communicate with other communication systems via any suitable means,such as by utilizing aspects of the systems described in InternationalPublication Nos. WO/2010/144900; WO 2013/043661 and/or WO 2013/081985,and/or U.S. Pat. No. 9,126,525, which are hereby incorporated herein byreference in their entireties.

Changes and modifications in the specifically described embodiments canbe carried out without departing from the principles of the invention,which is intended to be limited only by the scope of the appendedclaims, as interpreted according to the principles of patent lawincluding the doctrine of equivalents.

The invention claimed is:
 1. A camera module for a vehicular visionsystem, said camera module comprising: a front camera housing comprisinga housing portion and a cylindrical lens barrel extending from saidhousing portion; a lens comprising a plurality of optical elementsaccommodated in said lens barrel; an imager printed circuit boardaccommodated in said front camera housing, said imager printed circuitboard having an imager disposed thereat; wherein said imager printedcircuit board is attached at the front camera housing; wherein, withsaid imager printed circuit board attached at the front camera housing,said imager is optically aligned with an optical axis of said lens;wherein said housing portion of said front camera housing includesmounting structure configured to mount said camera module at a vehicle;a rear camera housing mated with said housing portion of said frontcamera housing so as to encase said imager printed circuit board in saidcamera module; and wherein said lens barrel comprises a material havinga lower coefficient of thermal expansion as compared to the material ofthe front camera housing.
 2. The camera module of claim 1, whereincircuitry of said camera module is electrically connected to said imagerand is electrically connected to electrical connecting elements that areconfigured to electrically connect to a wire harness of the vehicle whensaid mounting structure mounts said camera module at the vehicle.
 3. Thecamera module of claim 1, wherein said camera module is configured to bedisposed at an exterior portion of the vehicle so as to have a field ofview exterior of the vehicle.
 4. The camera module of claim 1, whereinsaid rear camera housing comprises a heat sink.
 5. The camera module ofclaim 4, comprising a heat transfer element that is in contact with saidheat sink of said rear camera housing and that is in contact with a rearside of said imager printed circuit board opposite from said imager. 6.The camera module of claim 1, wherein said imager printed circuit boardevenly distributes heat about the optical axis of said optical elements.7. The camera module of claim 1, wherein said imager printed circuitboard and at least one other printed circuit board evenly distributeheat about the optical axis of said optical elements.
 8. The cameramodule of claim 1, wherein said optical elements are bonded to aninternal surface of said lens barrel.
 9. The camera module of claim 1,comprising a bridge member between said lens barrel and said imagerprinted circuit board to accommodate different amounts of thermalexpansion of components of said camera module.
 10. The camera module ofclaim 1, comprising a moisture reducing element that limits internalcondensation at cooled components of said camera module.
 11. The cameramodule of claim 10, comprising a heat spreading material disposedbetween the moisture reducing element and an internal surface of saidrear camera housing.
 12. The camera module of claim 1, wherein saidfront camera housing comprises a plastic material.
 13. A camera modulefor a vehicular vision system, said camera module comprising: a frontcamera housing comprising a housing portion and a cylindrical lensbarrel extending from said housing portion; a lens comprising aplurality of optical elements accommodated in said lens barrel; animager printed circuit board accommodated in said front camera housing,said imager printed circuit board having an imager disposed thereat;wherein said imager printed circuit board is attached at the frontcamera housing; wherein, with said imager printed circuit board attachedat the front camera housing, said imager is optically aligned with anoptical axis of said lens; wherein said housing portion of said frontcamera housing includes mounting structure configured to mount saidcamera module at a vehicle; a rear camera housing mated with saidhousing portion of said front camera housing so as to encase said imagerprinted circuit board in said camera module; wherein said lens barrelcomprises a material having a lower coefficient of thermal expansion ascompared to the material of the front camera housing; wherein circuitryof said camera module is electrically connected to said imager and iselectrically connected to electrical connecting elements that areconfigured to electrically connect to a wire harness of the vehicle whensaid mounting structure mounts said camera module at the vehicle; andwherein said camera module is configured to be disposed at an exteriorportion of the vehicle so as to have a field of view exterior of thevehicle.
 14. The camera module of claim 13, wherein said rear camerahousing comprises a heat sink.
 15. The camera module of claim 14,comprising a heat transfer element that is in contact with said heatsink of said rear camera housing and that is in contact with a rear sideof said imager printed circuit board opposite from said imager.
 16. Thecamera module of claim 13, wherein said optical elements are bonded toan internal surface of said lens barrel.
 17. The camera module of claim13, comprising a bridge member between said lens barrel and said imagerprinted circuit board to accommodate different amounts of thermalexpansion of components of said camera module.
 18. The camera module ofclaim 13, comprising a moisture reducing element that limits internalcondensation at cooled components of said camera module.
 19. The cameramodule of claim 18, comprising a heat spreading material disposedbetween the moisture reducing element and an internal surface of saidrear camera housing.
 20. The camera module of claim 13, wherein saidfront camera housing comprises a plastic material.
 21. A camera modulefor a vehicular vision system, said camera module comprising: a frontcamera housing comprising a housing portion and a cylindrical lensbarrel extending from said housing portion; a lens comprising aplurality of optical elements accommodated in said lens barrel; animager printed circuit board accommodated in said front camera housing,said imager printed circuit board having an imager disposed thereat;wherein said imager printed circuit board is attached at the frontcamera housing; wherein, with said imager printed circuit board attachedat the front camera housing, said imager is optically aligned with anoptical axis of said lens; wherein said housing portion of said frontcamera housing includes mounting structure configured to mount saidcamera module at a vehicle; a rear camera housing mated with saidhousing portion of said front camera housing so as to encase said imagerprinted circuit board in said camera module; a heat transfer elementthat is in contact with said rear camera housing and that is in contactwith a rear side of said imager printed circuit board opposite from saidimager; wherein said lens barrel comprises a material having a lowercoefficient of thermal expansion as compared to the material of thefront camera housing; and wherein circuitry of said camera module iselectrically connected to said imager and is electrically connected toelectrical connecting elements that are configured to electricallyconnect to a wire harness of the vehicle when said mounting structuremounts said camera module at the vehicle.
 22. The camera module of claim21, comprising a bridge member between said lens barrel and said imagerprinted circuit board to accommodate different amounts of thermalexpansion of components of said camera module.
 23. The camera module ofclaim 21, comprising a moisture reducing element that limits internalcondensation at cooled components of said camera module.
 24. The cameramodule of claim 23, comprising a heat spreading material disposedbetween the moisture reducing element and an internal surface of saidrear camera housing.
 25. The camera module of claim 21, wherein saidfront camera housing comprises a plastic material.